SOLUTION: one of the angles of a parallelogram is 40 degrees. what is the measure of one of the obtuse angles? why?

Question 141471: one of the angles of a parallelogram is 40 degrees. what is the measure of one of the obtuse angles? why?

Answer by jojo14344(1513) (Show Source): You can put this solution on YOUR website!
Well, the opposite angle should be another 40 degrees. Now the obtuse angle should be 140 degrees, of course likewise opposite of it is 140 degrees too.
One property of a parallelogram being that opposite angles are congruent.
Why 140 degrees?
Let's say ABCD is a parallelogram. Angle A is 40 degrees and opposite which is angle C is also 40 deg. Now outside of angle A is 140deg (bec. 140+40=180) and that 140 deg is equal to angle B which is congruent to angle D.Therefore, angle B=140deg and angle D= 140deg
The sum of all included angles should be 360 degrees, which is right.
A+B+C+D=40+140+40+140=360deg
Thank you,
Jojo
RELATED QUESTIONS
A parallelogram has two obtuse angles and two acute angles. Of the measure of one of the... (answered by LinnW)

a parallelogram has two obtuse angles and two acute angles.if the measure of one of the... (answered by richwmiller)

A pentagon has two right angles, two obtuse angles that are congruent, and a fifth angle... (answered by richard1234)

If one angle of a parallelogram is 40�what is the measure of the other angles? (answered by KMST)

Two angles are supplementary. If one of the angles measures 40 degrees, what is the... (answered by Alan3354)

two angles in a parallelogram measure 80 degrees. What is the measure of the other two... (answered by ccrox)

One of the angles of a parallelogram is26�.What is the difference between the adjacent... (answered by Boreal)

Two angles are Complementary. If one of the angles is 15 degrees, what is the other... (answered by fcabanski)

The sum of the measures of 3 angles is 180 degrees. If one of the angles is a right... (answered by solver91311)